Fluorescent microparticles with controllable enhanced stokes shift

ABSTRACT

The invention relates to methods for labeling or detecting one or more target materials using surface coated fluorescent microparticles with unique characteristics. The unique microparticles used to practice the invention have at least two components: an external substance or coating that is selective for each target material and an internal mixture of multiple fluorescent dyes. The mixture of dyes is a series of two or more fluorescent dyes having overlapping excitation and emission spectra allowing efficient energy transfer from the excitation wavelength of the first dye in the series, transfer through the dyes in the series and re-emitted as an optical signal at the emission wavelength of last dye in the series, resulting in a desired effective Stokes shift for the microparticle that is controlled through selection of appropriate dyes. The unique microparticles are combined with a sample thought to contain the target material(s), so that the microparticles label the target materials. The sample is then optionally illuminated, resulting in fluorescence of the microparticles that is used to detect one or more target materials.



